Anatomy and Physiology Quiz 3

Circulatory System

Transportation of oxygen, nutrients, hormones, and other essential substances throughout the body. Removal of CO2 and other waste products associated with organ function or metabolism.

Pulmonary Circulation

right side, lower pressure

Systemic Circulation

Left side, higher pressure

Venous return pathways

low pressure, pushes blood back to heart for reoxidation

Auricular surface

left surface

Atrial surface

Right surface

artery

take blood from the heart

vein

return blood to heart

Semilunar valves

has pulmonary and aortic

atrioventricular valves

right (also called right AV, tricuspid) and left (left AV, mitral, bicuspid)

systole

contraction of myocardium

diastole

relaxation of myocardium

Atrial filling (Diastole)

blood comes into the right atrium from the body (vena cavae)

blood comes into the left atrium from the lungs (pulmonary veins)

Atrial contraction (systole)

blood goes from the right atrium to the right ventricle via the right AV valve

blood goes from the left atrium to the left ventricle via the AV valve

Ventricular Contraction

blood flows from the right ventricle to the lungs via the pulmonic valve and pulmonic artery

blood flows from the left ventricel to the body via the aortic valve and aorta

Cardiac Cycle

1. Ventricular contraction>AV valves close, pressure increases> aortic/pulmonary valves open> ejection (systole)

2. ejection slows, contraction ends, ventricles relax (diastole)

3. ventricular pressure drops rapidly, aortic and pulmonary valves close, AV valves open (diastole)

4. atrial and ventricular filling (blood flows freely into ventricles when AV valves are open) (diastole)

5. Atria contract first, “tops off” ventricle (systole)

Ventricular Diastole

ventricular relaxation, S3 (ventricular filling), S4 (atria contract)

Ventricular Systole

ventricular contraction, S1 “lub” (AV valves closing at beginning), S2 “dub'“ (aortic/ pulmonary valves closing at end.

sino-atrial node (SA node)

pacemaker, first place of delocalization, located in right atrium near cranial vena cava, controls the depolarizations of the heart muscle, heart rate, depolarization spreads across both atriums

atrial-ventricular node (AV node)

second area of depolarization in the septum between the atriums, conducts depolarization down the ventricular muscles

bundle of his

coordinates depolarization of ventricular cells

purkenje muscles

the transmission between cardiac cells allows coordinated muscle contraction to eject the chambers

heart location

within thorax (with base dorsally and apex ventral-caudal) inside mediastinum

mediastinum

the space created between the right and left lung

Cardiac Auscultation

S1: left and right AV valve closure

S1-S2 interval: systole

S2: aortic and pulmonary valve closure

S2-S1 interval: diastole

heart murmurs

turbulent blood flows. Stenosis or valvular insufficiency. Identify phase of cardiac cycle and possibly source based on volume at different sites on chest wall

serous layers: pleura

squamous cell layers, allows lungs to contract and expand at ease, slimy layer. Continuous layer covering all aspects of the thoracic cavity. Named for the region it covers. Costal (ribs), mediastinal, pulmonary (lungs), diaphraagmatic

pericardium

has serous and fibrous layers

pericardial cavity

space between the pericardium and the visceral serous pericardium

Pericardial sac

1. mediastinal pleura

2. fibrous pericardium

3. parietal serous pericardium

4. pericardial cavity

5. visceral serous pericardium (epicardium)

6. myocardium

7. endocardium

epicardium

the covering of the heart, it is an epithelial tissue. It is the same as the visceral pericardium

myocardium

cardiac muscle

endocardium

lines the inside chamber of the heart. It is also an epithelial tissue but is referred to as “endothelium”

elastic arteries

elastic connective tissue

arterioles

smooth muscles direct blood flow into capillary beds (tiny arteries)

Capillaries and capillary bed

walls are composed of endothelium, allows passage of single file red blood cells, allows exchange of fluid, oxygen, and nutrients with the tissue by two methods.

venules

small and thin walled, joined to capillary beds

veins

larger in diameter than arteries, small amount of smooth muscle in walls, one way valves direct flow back to heart, low pressure system because the veins don’t have oxygen, returns to right heart via the cranial and casual vena cava

Vena puncture sites: dog

cephalic vein on the medial forearm, jugular-jugual furrow of neck, lateral saphenous-lateral hock, medial saphenous-medial thigh (good for small amounts or IV injections on cats)

vena puncture sites: large animal

jugular, tail vein, cranial superficial milk vein

Blood Pressure

Directly related to the flow and the resistance or friction in the system. Closed system with heart muscle creating the initial flow with the force of contraction. Elastic arteries maintain flow (pressure) with rebound of elastic tissue. Smaller arteries with smooth muscle influence pressure by changing the lumen size of vessels

Parasympathetic influences

inhibits heart rate, slows depolarization (contractions) of SA node

Sympathetic influences

stimulate heart rate, increases rate of depolarization (contractions)of SA node

Stretch receptors

carotid and aortic sinus contain stretch receptors. Transmit afferent impulses to cardio-inhibitory center of the medulla. Results in decreased heart rate and causes peripheral vasodilation in response to stretching of these areas.

Marey Law

heart rate is inversely related to arterial blood pressure. Rises= drop in heart rate. Falls= rise in heart rate.

Bainbridge Reflex

reflex that occurs in response to increased exercise and greater venous return to the heart. Right atrium is stretched and causes an increase in heart rate

Starlings Law

increased volume returned to the heart will cause an increase in strength of cardiac contraction

Blood Components

formed elements (cells and cell fragments) which are suspended in the liquid fraction known as plasma

3 General Functions of Blood

1. transportation: oxygen, carbon dioxide, nutrients, wastes, and hormones

2. regulation: pH, temp, osmotic pressures

3. protection: against foreign molecules and diseases, as well as for clotting to prevent excessive loss of blood

Functions of Blood

transport, buffer, homeostasis, nutrition, excretory, host defense, fluid volume, temperature regulation, clotting

Components of Blood

erythrocytes, leukocytes (granulocytes and agranulocytes), thrombocytes, plasma (water and dissolved substances)

Hematocrit or packed cell volume (PCV)

RBC layer, plasma, buffy coat, relationship of fluid component of blood to RBC to determine anemia and dehydration

Blood color

hemoglobin and bilirubin

Blood volume

8-10% lean body weight

serum

liquid that remains after the blood has clotted

plasma

liquid that remains when clotting is prevented with the addition of an anticoagulant

blood pH

hydration of carbon dioxide in venous blood results in higher numbers of free hydrogen ions. Hydrogen ion concentrations in venous blood vs arterial blood is buffered in the blood using bicarbonate. Carbon dioxide produced by metabolism and is expelled with respiration allowing for buffering of blood pH by control of bicarb and hydrogen

Erythrocytes or RBC

appear as bi-concave disks with no nucleus. Synthesizes hemoglobin as immature cells

Hemoglobin

4 heme molecules, 4 amino acid chains of globin proteins, 4 atoms of iron. Each molecule of heme can carry an oxygen molecule associated with each iron molecule. 4 oxygen molecules per _____. (called oxy____)

Oxygen carrying capacity

60 fold carrying capacity of oxygen over that of water. Only 1.5% of O2 in blood is dissolved directly into the blood itself

Regulation of Erythrocytes

Produced in bone marrow, erythropoietin is released from kidneys in response to low O2 levels. Stimulates red blood cell production. Time delay of 3-5 delay to respond and release mature RBCs.

Red blood cell life span

120 days

Heme in erythrocytes

biliverdin, bilirubin conjugated with proteins and excreted by the liver as bile or by the kidneys as urobilinogen

Globin in erythrocytes

digested as proteins

Iron in erythrocytes- transferrin

stored in bone marrow

Iron in erythrocytes- ferritin

stored in the liver

iron in erythrocytes- hemosiderin

stored in the tissues

Thrombocytes function

act as a physical plug to prevent blood loss, initiates the clotting cascade

Thrombocytes regulation by bone marrow

thrombopoiten produced by the liver and kidneys and adheres to the platelet. When the total mass of platelets falls, bone marrow responds

Thrombocytes response time

4-5 days

Thrombocytes life span

10 days

Size order of thrombocytes

neutrophil> erythrocytes> platelets

Basophil appearance

more globular nucleus

Neutrophil appearance

more sausage link nucleus

Eosinophil appearance

stains red, two big nuclei

Granulocytes

Part of leukocytes, contains neutrophils, eosinophils and basophils.

Granulocyte functions

innate defense, margination, chemotactic substances, diapedesis

Agranulocytes

macrophages, monocytes, lymphocytes (T and B cells)

Agranulocyte functions

acquired immune response, antibody production

Neutrophils

produced in the bone marrow, takes 5 days to mature. Colony stimulating factors or leukopoietic factor released from dead neutrophils and other dying cells

Neutrophils life span

10 hours in blood stream, 5 day supply of mature neutrophils

Neutrophils function

Mature neutrophils housed in the bone marrow as a reserve supply, bone marrow reserve released into circulation in response to chemicals of inflammation, reserve supply can increase circulation numbers by several billion

Eosinophil life span

8-12 days

Eosinophil function

parasites and allergies

Basophil life span

a few days

Basophil function

response to histamine

Agranulocytes

monocytes

agranulocytes life span

hours to days in circulation

agranulocytes function

move out of the blood to tissues to transform into macrophage, osteoblast, reticuloendothelial system of spleen and lymph nodes, Kuppfer cells in the liver

Lymphocytes life span

years for memory cells, days in circulation

Lymphocyte T-cells

CD 4, CD 8, suppressor or regulatory, natural killer cells

Lymphocyte B-cells

makes antibodies and activates T-cells

Plasma proteins function

buffer, colloidal osmotic pressure

albumin

produced by the liver, carries calcium ions in the plasma, large molecule that helps with osmotic pressure

globulin

antibodies produced by lymphocytes and plasma cells (alpha globulin, beta globulin, gamma globulin)

Transportation function of blood: metabolic substances

oxygen, glucose, amino acids, fatty acids, various lipids

Transportation function of blood: waste removal

carbon dioxide, lactic acid, nitrogenous wastes of protein metabolism, and heat

Transportation function of blood: additional products

transports water and essential electrolytes including Na+, Cl-, K+, Ca2+, H+, and HCO3-

diffusion

movement along a concentration gradient (temperature gravity, concentration) SOlute goes from high to low concentration

osmosis

movement across a membrane, solvent goes from low to high concentration